PH Swing

[ncsaltwater]

I am having a problem with higher than normal PH readings and am looking for some input. The PH from reading goes from 8.2 w/ lights off to 8.5 at the end of the day

Tank Conf.
SPS dominate system
Tank location – Charlotte NC
The system is an in the wall tank where everything is in a closed room in the garage.
260G total system water volume (180G main display, 40G sump, 40G frag tank)
3 -400 Radium MH lights over Main tank
1 – 250 14k Phoenix bulb over frag tank
Ca Reactor using (Gen-X CRM media) – PH output 6.7
Kent Phosban Reactor running 13tsp Rowaphos
Kent Reactor running carbon
Flow – Main return – Sequence Barracuda running dialed back ¼ of the way,
Closed Loop running w/ Sequence Hammerhead dialed back ¼ of the way.
Light timings – Supplemental lights 3-65w PC turn on between 11:30am and 1:00pm, 3 MH turn on between 2:00pm and 3:00pm, MH turn off at 8:00pm and Supplemental at 10:00pm

Tank Parameters are as follows
Salinity – 35ppm
NH4 – 0
NO2 – 0
NO3 – 5
PH4 – 0
MG – 1150
CA – 420
DKH – 12
Tank Temp 78-80

Things I don’t do
Dose Kalk
I don’t dose any other Supplements

I’m looking for ideas on how I can narrow the PH swing in the tank.

[Rovert]

You might try running an inverse photoperiod on the frag tank, and/or set up a macroalgae laden refugium and also run the photoperiod opposite the main tank.

[ncsaltwater]

Dude I understand the

"You might try running an inverse photoperiod on the frag tank"

Good point

But what is a "macroalgae laden refugium"?


__________________

[JackKerouac]

just a connected tank to your main system with macroalgae inside,some algae like Chaetomorpha will do a good job

[Rovert]

LOL!

No, that wasn't German.

A refugium heavily laden (filled with) macroalgae. I'll presume you know what a 'fuge is.